In Budapest we had a space for a few days in a very vertical car park, a term a I like better than parking garage. There was an in-door, electronically controlled on one street, and an out-door on the parallel street, plus a pedestrian door. It had a tiny elevator and a set of stairs going all the way to the top. Every floor had some windows, so it wasn't always completely dark, but it was never more than half-dusk. The ramp was quite steep and the turns were sharp: it was hard to get around the corners in our little SUV without some going forward and backing up, especially when someone had put their motorcycle in the little crannies by the curve. There were not distinct floors, just really flatter parts of the ramps, one going up and one going down, so you could look across the from 4A to 4B which was going up while you were going down. If you built a house in there is would have been a split-level, like the one I lived in in Lake Oswego, OR, in the late 1960s. There were cars at every level, but plenty of empty spaces too. The car park did not belong to any one building, it was a rental space used by pensions in the neighborhood and by residents with cars.
What happens to the car park when there's not enough fuel, or it costs too much, to operate a car. What kind of thing does a car become? My thought was that the car park might become a squat of sorts, then a village, or a neighborhood, in the larger post-car city. The demise of cars would probably produce more centralization of population, as commuting became less viable -- this gives me another story to think about with respect to the suburbs returning to "nature." Homesteading was an American tradition, sanctioned by the government as a way of civilizing the world. Squatting now is condoned insofar as it reclaims space often used for ill, and gets some number of folks off the street, where they are unsightly and a danger to themselves and others. Someone with a car that couldn't be driven would probably just live it in the park, rather than incur the expense of moving it somewhere else. So living in the abandoned cars would be a form of recycling. If one had an enlightened government, and we need to assume anarchy, then squatting in the car park could be condoned if not even supported in some way, perhaps just passively.
So the setting is a post-petroleum city, but not a post-energy city. And certainly not a post-digital city, meaning that global communication remains feasible while global travel is more difficult, though perhaps not impossible. That's the premise.
The story question is what sorts of social and personal challenges might be involved in this pioneering, and who would be involved. I'm thinking of three groups of people: the Gypsies, the art&musics, and the magic. The specific problem I was thinking of had to do with kids and their recreation, tangled up in the virtual v. real.
So the plot comes from a game that the kids create, partly from a video-game. Skating and skate-racing, all because someone has a copy of some skate game software the kids have found, and have started playing. There's even some online playing between those on the top of the park and those on the bottom. But band-width is a limited resource, so some of this playing is a violation. Then some kid scrounges a board, and others start producing, or scrounging more boards. Eventually there are kids skating from the top to the bottom, a dangerous and exciting and annoying to the adult resident thing to do. So here's two conflicts: the social conflicts about using limited resources, about unregulated and risky play, and between those who prefer the real and those who prefer the virtual. This requires four or five adolescent characters and some related adults.
Voila, the premise of a story. How does it resolve? In my first paragraphs, I said it led to a death, but I didn't say and didn't know whose or under what circumstances. Or what the consequences of the death might be to the game or to the world.